牛羊混合放牧对荒漠草原植物群落特征的影响

Effects of Mixed Grazing on Plant Community Characteristics in Desert Steppe

2012～2013年在希拉穆仁草原牧草生长季,通过设置不同放牧方式（牛单牧、羊单牧、牛羊混合放牧和无牧）研究其对荒漠草原植物群落特征的影响,结果表明：随着放牧年限的延长,放牧方式对群落特征产生了一定的影响.2012年牛单牧、牛羊混合放牧和羊单牧的草群高度分别为6.16cm、6.34cm和8.55cm,2013年分别为5.11cm、4.62cm和5.50cm.2012年各处理植物群落盖度较高且差异很大,2013年各处理植物群落盖度有所下降并趋于一致.2012年牛单牧和牛羊混合放牧都降低了植物群落密度,2013年牛羊混合放牧却使植物群落密度增加.2012年牛单牧、混合放牧和羊单牧的地上生物量分别为53.9g/m2、57.8g/m2和69.6g/m2,201 3年为59.9g/m2,53.1g/m2和72.3g/m2,牛单牧和混合放牧与羊单牧比较均表现为下降趋势（P＜0.05）.群落多样性指数分析表明,在适度放牧的情况下牛羊混合放牧可以较好地维持植物群落的多样性.

This experiment was conducted to investigate the effects of grazing system （single sheep or cattle grazing, mixed grazing of cattle and sheep） on plant community characteristics in desert steppe of Xilamuren grassland in Inner Mongolia from 2012 to 2013. The results indicated that grazing system affected the community characteristic significantly. The community height under cattle grazing, mixed graz- ing and sheep grazing were 6.16cm, 6.34cm and 8.55cm in 2012, respectively, and 5.11cm.4.62cm and 5.50cm in 2013, respectively. The plant community cover under grazing treatments differed significantly in 2012, whereas decreased and did not differ in 2013. The plant community density decreased under cattle grazing and mixed grazing in 2012, whereas increased under mixed grazing in 2013. The above-ground biomass of community decreased under cattle grazing and mixed grazing with 54. 9g/m2 and 57. 8g/m2 in 2012, and 53. lg/m2 and 59.9g/m2 in 2013, respectively compared with sheep grazing. The mixed grazing improved the plant community diversity.